Conventionally, in cable-driven elevator systems with a plurality of lift passages or "shafts," various kinds of so-called "elevator group management" schemes have been provided in order to increase the transportation efficiency. The elevator group management schemes are to manage or control traveling of elevator platforms or cars (referred to as "cars" hereinafter) not by letting these cars respond individually to landing-place or "station" calls in a car-to-shaft correspondence manner but by determining an appropriate car that should respond to a station call by taking account of the actual traveling conditions of individual cars moving in respective shafts associated.
In the recent years advanced elevator systems have been proposed in order to achieve further enhanced transportation efficiency, one of which is a vertical/transversal movable elevator group control system as has been disclosed in, for example, Published Unexamined Japanese Patent Application (PUJPA) No. 62-275987 and PUJPA No. 3-216477. This system disclosed is the one capable of causing a plurality of cars to move or travel in a single shaft by use of linear motors while allowing them to transversely shift among the shafts. Such elevator system is becoming more attractive in practical applications due to its advantage: the allowable transportation amount can be much improved due to the fact that it enables associative transportable cars to increase in number as compared to the prior known cable-driven elevator systems insofar as the shafts in both systems is identical in number.
Furthermore, the elevator group management control apparatus and the elevator group management control method used in this type of vertically- and horizontally-movable elevator system, such as the one disclosed in PUJPA No. 5-9173, are designed on the concept that a car moves in one direction only (upward or downward) in each shaft and that a car moves in a loop.
In the vertical/transversal movable elevator group control system, the system design is established under the assumption that a plurality of cars are moving in one shaft while permitting their crosswise movement among these shafts; this will possibly lead to occurrence of collision between adjacent ones of the cars. To avoid such collision, especially to retain maximized safety for passengers, several transportation management methods have been developed: one approach is to force the cars to decrease in moving speed eliminating collision by use of a car position detector means; and, another approach is to force the individual car to stop at an appropriate position that may exclude the risk of occurrence of collision.